The present invention relates to an thin-film electroluminescent display panel and, more particularly, to a thin-film electroluminescent display panel shielded by a pair of glass substrates and a protective liquid disposed therebetween.
A conventional thin electroluminescent (EL) display panel sealed by a pair of glass substrates and a protective liquid is disclosed in Kawaguchi et al, U.S. Pat. No. 4,213,074 issued July 15, 1980, assigned to the common assignee and entitled "THIN-FILM ELECTROLUMINESCENT DISPLAY PANEL SEALED BY GLASS SUBSTRATES AND THE FABRICATION METHOD THEREOF". The disclosure of this patent is incorporated herein by reference.
In the structure of the thin EL display panel, it is very important and necessary to prevent any moisture from penetrating into the housing of the display panel defined by the pair of glass substrates. The presence of the moisture mainly lowers the intensity of the EL light from the EL display panel.
In this respect, the above patented structure of the EL display panel inherently had the disadvantages that since a transparent electrode under an EL thin film is conventionally made of In.sub.2 O.sub.3 or SnO.sub.2 etc. which is rather porous because of high crystallization, some moisture from the atmosphere can easily penetrate and diffuse into the housing of the EL display panel through the transparent electrode. The transparent electrode extends from the inner side of the housing to the outer side through the bonded connection between the pair of glass substrates.
Therefore, it is highly desired to completely shut out any moisture from penetration into the interior of the housing.